The present invention relates to a method and apparatus for controlling the unwanted growth of auxiliary buds on plants. Such auxiliary buds are also referred to as xe2x80x9csuckers.xe2x80x9d The present invention also relates to a method and apparatus for reducing maleic hydrazide residues in tobacco, reducing the xe2x80x9ctoppingxe2x80x9d operations that tobacco farmers need to execute in order to control tobacco suckers, reducing the exposure of tobacco laborers to chemicals, and reducing the amount of chemicals used in the tobacco industry.
In order to obtain maximum yields of flue-cured and burley tobacco in the United States, the plants are xe2x80x9ctoppedxe2x80x9d by removing the flowers or flower buds before harvest. However, the removal of these flowers allows auxiliary buds or xe2x80x9csuckers,xe2x80x9d to flourish. It is desirable to prevent the growth of suckers. Currently, such growth is inhibited by using a combination of xe2x80x9ccontactxe2x80x9d and xe2x80x9csystemicxe2x80x9d plant growth regulator chemicals. Usually, at least two or three applications of this xe2x80x9ccontactxe2x80x9d chemical are applied, followed by an application of the xe2x80x9csystemicxe2x80x9d chemical. Maleic hydrazide is the only strictly systemic plant growth regulator that is currently available. All of such chemicals are sprayed over the top of the tobacco plants. Some chemicals in the market are a combination of systemic and contact types. Over one half of the tobacco produced in the United States is xe2x80x9ctoppedxe2x80x9d mechanically by using high-clearance equipment with rotating cutter blades.
The problems associated with the known method and apparatus include: (1) necessary repeated applications of the plant growth regulator over the tobacco field; (2) high pesticide use; (3) worker exposure to pesticides; and (4) maleic hydrazide residues in the cured leaf. The latter problem is of utmost concern among growers, manufacturers, and exporters of tobacco. Maleic hydrazide is applied at 1.5 gallons product per acre (1.5 pounds active ingredient per gallon) in thirty to fifty gallons water per acre. Industry regulations imposes strictly held constraints pertaining to the maximum percentage amount of maleic hydrazide permissible in a cured tobacco leaf. Weather conditions, cultural practices, and improper use of maleic hydrazide often lead to residues unacceptable to domestic and foreign buyers.
The following are U.S. Patents concerning agricultural cutting and chemical application devices:
Mote, U.S. Pat. No. 2,111,030, teaches a device for distributing chemicals for destroying insect pests which is also capable of harvesting crops of various habits of growth and various sizes.
Mullin, U.S. Pat. No. 2,908,444, teaches a spraying attachment device for rotary lawn mowers which can dispense liquid material to a confined and controlled area of the gardener""s choosing.
Mullin, U.S. Pat. No. 2,939,636, teaches a device which provides a spraying means adapted for converting a liquid material into a fine spray or mist and for forcibly directing such spray downwardly against a well defined area of ground being traversed with the spray being applied to the ground in substantially uniform quantity throughout such area.
Yaremchuk, U.S. Pat. No. 2,973,615, teaches a device which combines a liquid weed-eradicating device with a power driven rotary lawn mower for better distribution of the liquid by the mower blade over the area covered by the machine in its movements such that the liquid is vaporized to a great extent for effective application to the weeds under the mower.
Quick, U.S. Pat. No. 3,462,927, teaches a device controlled by the operator of a cane harvesting machine for causing the severed tops of cane stalks to be discharged either to the right or to the left of the harvesting machine. A pair of guide bars is located in the throat formed by the gathering drums and adjustably mounted so that the severed cane tops will be directed into the influence of one selected gathering drum and thus discharged on a selected side of the machine.
Makeham, U.S. Pat. No. 3,596,447, teaches a harvesting machine particularly for cutting the tops off a standing crop, the cutting apparatus including a pair of knife discs rotatable on substantially vertical axes and having a slight overlap in cutting areas. A pivoted vertically extending guide vane directs cut material toward one knife or the other. A drum is carried above each knife and rotates therewith. The drum has radially extending crop moving paddles thereon. Curved vertically extending guide plates are located to the rear of the drum and intersect at the pivot axis of the guide vane. The knives and drum are individually driven and means are provided to move the guide vane.
Willett, U.S. Pat. No. 3,760,569, teaches a cane topping device for simultaneously topping two rows of cane being cut by a V-cutter harvester wherein overlapping cutters are raised and lowered to compensate for varying cane stalk height and the angle of attack of the cutting blades of the topper may be varied.
Vicendese, U.S. Pat. No. 3,942,308, teaches a combination power driven lawn mower and lawn care chemical dispensing machine in which a hopper for dry granular chemicals is affixed to the top of the lawn mower frame in such a manner that the chemical may be dispensed over an area defined by the swath of lawn cut by the blade.
Otten, U.S. Pat. No. 5,131,216, teaches a device for separating the shoot tips of sugar-cane plants for multi-row sugar-cane harvesting machines. The device includes feed-and-cutting elements mounted in front of a trough-like table having a cross-conveyor worm which receives the tip portions and conveys them to the side. The feed-and-cutting-elements have two feed discs equipped with prongs which interact respectively with a respective cutting disc.
The invention provides a method and apparatus for simultaneous topping of tobacco plants while applying sufficient growth-regulator chemical(s) for adequate sucker control. The invention is a non-spray system that may use systemic growth retarding compounds. A rotating or reciprocating blade is continuously moistened with retarding agents. While cutting the plant, the invented system simultaneously delivers enough chemical to kill or prevent the growth of auxiliary buds into suckers and prevents future growth after topping.
The invention further provides a method and apparatus for simultaneously topping tobacco and controlling suckers that results in a savings to the grower since less chemical and fewer trips over the field are needed.
The invention further provides a method and apparatus for simultaneously topping tobacco and controlling suckers that accommodates accurate application of chemicals that are applied directly to the cut stem.
The invention further provides a method and apparatus for simultaneously topping tobacco and controlling suckers that eliminates off-target pesticide drift.
The invention further provides a method and apparatus for simultaneously topping tobacco and controlling suckers that reduces worker exposure to chemicals.
The invention further provides a method and apparatus for simultaneously topping tobacco and controlling suckers that eliminates maleic hydrazide residues in cured tobacco leaves. The low tolerance of residues imposed by domestic and foreign buyers, which in turn is due to major competitors for American style tobacco that do not use maleic hydrazide for sucker control, currently threatens the United States tobacco industry. Publication 1997 Flu-cured Tobacco Information published North Carolina Cooperative Extension Service Bulletin AG-187 (1996) is incorporated herewith by reference and contains information useful to the reader concerning this question.
The invention further provides a method and apparatus for simultaneously topping tobacco and controlling suckers that eliminates failures of sucker control with maleic hydrazide due to rain wash off or drought conditions.
The invention further provides a method and apparatus for simultaneously topping tobacco and controlling suckers that may be mounted on or adapted to currently available high-clearance equipment used in tobacco fields for mechanically topping tobacco plants.
The principal object of the present invention is to provide means for producing xe2x80x9csaferxe2x80x9d tobacco than is now produced.
Another is to provide a method for reducing maleic hydrazide residue in harvested tobacco leaves.
Another object of the invention is to provide a process that eliminates existing maleic hydrazide spraying.
A further object of this invention is to provide an elimination of the exposure of chemicals to tobacco workers.